cervix
(SER-vix)
The lower, narrow end of the uterus (womb) that connects the uterus to the vagina (birth canal). The cervix allows fluids, such as menstrual blood, to pass from the uterus into the vagina. It also widens during the birth of a baby. The cervix has two main parts, the ectocervix and the endocervix. The ectocervix is the outer part of the cervix that can be seen during a pelvic exam. The endocervix is the inner part of the cervix that forms a canal that connects the vagina to the uterus. The area where the endocervix and ectocervix come together is called the squamocolumnar junction (also called the transformation zone). Most abnormal cell changes and cervical cancers begin in the squamous cells (thin, flat-looking cells under a microscope) of the squamocolumnar junction.
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Enlarge this image in new windowAnatomy of the female reproductive system. The organs in the female reproductive system include the uterus, ovaries, fallopian tubes, cervix, and vagina. The uterus has a muscular outer layer called the myometrium and an inner lining called the endometrium.
Enlarge this image in new windowAnatomy of the cervix. The cervix is the lower, narrow end of the uterus that connects the uterus to the vagina. It is made up of the internal OS (the opening between the cervix and the upper part of the uterus), the endocervix (the inner part of the cervix that forms the endocervical canal), the ectocervix (the outer part of the cervix that opens into the vagina) and the external OS (the opening between the cervix and vagina). The area where the endocervix and ectocervix meet is called the squamocolumnar junction, which contains both glandular cells (column-shaped cells that make mucus) from the endocervix and squamous cells (thin, flat cells) from the ectocervix. The squamocolumnar junction is sometimes referred to as the transformation zone.